Trying a handheld thermal imager to find my cat at night

My cat Luna keeps slipping out at night, and I have been thinking about trying a small thermal imager to make it easier to find her in the yard. I have never used thermal imaging for this kind of search, but a neighbor told me it works much better once the background temperature drops. I am planning to test it later tonight to see if it actually helps.

For those who have used thermals to look for pets at night, what has worked best for you. Do you rely more on temperature contrast or movement when scanning the yard.